Pushblock has to be pushed off 4 click ledge, then continue the puzzle with it. But if you don't release Ctrl, she will just push on till you stop and then fall down. Then the block lost collision and you can't use it anymore because the collision stayed on the square where the block went of the edge. Titak told me of a condition trigger setup, just curious, are there more solutions for the problem?

there aren't fully working solutions, because it is a trng bug.
What I would do if I were you, in this case, is to put a wall sector in the sector just after the hole, so lara won't be able to push forward endlessly But let me know if this works..

Condition that Lara is pushing the block is true, then disable Action for ** seconds.
Place the condition trigger and the disable Action trigger on the tile in front of the tile where she can push the block off the ledge, or on that tile itself.

Stupid me has used something like this in my own levels, but can't figure out the exact setup anymore...
Checked the prj's and the script, but nothing.
But I think it was something like this.
By doing this, you prevent the Action button triggering the pushing animation again. So Lara will automatically stop pushing after the block has fallen, even when the Action button is still pressed by the player.

Nothing is in contradiction with nature,
only in contradiction with what we know of it.